DIY Audio Projects Forum

Welcome to the DIY Audio Projects Message Forum. Use these forums to discuss Hi-Fi audio and to share your DIY Audio Projects. Registration is free and required to post messages and view the file attachments. Registration will only take a minute and registered users do not see any advertisements. After you have completed the online registration process, check your email (including spam/junk folder) for the verification email to activate your account. New members are under moderation - so your posts will not be visible until approved by a moderator. See the Read Me 1st, Forum RULES and Forum FAQ to get started on the forum.

I cannot remember why I got the incredible idiotic idea to start this project. I guess some small influences from here and there sort of inspired me to get on with it. There were some discussions with another member of the forum about the transistors and some checking on the web the main component, the transistor seemed to be available. A bigger concern was the resistors. How to fins a 15 Ohm/50W resistor?!

To make a long story short, I ordered transistors "real Renesa" on eBay and ended up with crap, but I had understood that would be the case as I waited for the shipment. I also ordered some from a reliable source in Germany and they did work. As I need a few components for another project I will propably be back for some more, just in case ...

OK, back to the project. With all components in place (minus the proposed choke) I could finally start trying the proposed design. Mounted (a working) transistor on a heatsink, Passive components soldered on a small breadboards (the Chinese cannot fake those ...).I got a special made transformer (2x18V) cheaply from England (eBay), have som 10.000uF and rectifiers suitable for the job, but no appropriate chassis.

A quick setup gave good results immediately. There were no instructions how to set up the amplifier, but I guessed setting the pot in mid position would be fine for a start. Double and triple checked all connections; I managed to kill four Russian power tubes in ten minutes once, so I have learned the lesson, and learned it good.

Before showing to blurry photos taken by my semi-pro mirrorless Canon camera, a few notes. All components are according to original drawings, apart from the plastic caps across the output electrolytics. I could only dig up a pair of 2,2u, and I used 47uF caps on the bias voltage. The PSU isn't assembled as I feel I need a box to put everything in so I powered the amp by my PSU.

Here comes the pictures, as the project goes on I will send more details.

This is the experimental setup. Input grounded, PSU running at approx 24V and DMM across drain and source. All lokks perefctly well.

Attachment:

2SK1059_02.jpg

Now I have attached a potentiometer to the input, connected a speaker and my iPod and play some good music. Not that very loud but that may depend on the speakers.

Attachment:

2SK1059_01.jpg

I also want to thank KrammeAcoustics for good advices and help along the road, that was, actually really short. I have never managed to go from project start to a working device this quick.

This post has a file attachment. Please login or register to access it. Only Registered Members may view attached files.

_________________Magnus

“If you don't know where you are going, any road will get you there.”―Lewis Carroll

Will get #2 up and running an solve the housing problem. The problem is when you have the amp parts AND off-the-shelf heatsink.; it's hard to find a chassis that suits your needs. But I have decided to try to adopt the tube-like way of mounting stuff.

A friend of mine who teached tech-stuff at a high school had his students to build a one-transistor amp. Guess he used a darlington like BDX33 or 34. Many students meant that their simple stuff sounded much better than their parents 5.1 home theatre systems from Bose.

_________________Magnus

“If you don't know where you are going, any road will get you there.”―Lewis Carroll

Who is online

Users browsing this forum: No registered users and 6 guests

You cannot post new topics in this forumYou cannot reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum